


Time is of the Essence

by cookieboo



Series: Brought Together by Stone [2]
Category: Dr. STONE (Manga)
Genre: F/M, Fluff, Modern AU, Romance, Slow Burn, childhood AU
Language: English
Status: Completed
Published: 2020-01-13
Updated: 2020-01-13
Packaged: 2021-02-27 09:48:46
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,609
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22235116
Author URL: https://archiveofourown.org/users/cookieboo/pseuds/cookieboo
Summary: Just a flashback to the good old days as Senku's childhood friend. The growing dynamic of a future doctor,  a future scientist and their growing love.
Relationships: Ishigami Senkuu/Reader
Series: Brought Together by Stone [2]
Series URL: https://archiveofourown.org/series/1601845
Comments: 1
Kudos: 98





	Time is of the Essence

“I know I fixed something..but what’s wrong? I swear these numbers are right..”

“Hey Senku, what are you working on?”

“I’m trying to make a suit for my dad. It will help stimulate his muscles to swim properly, even if he were to have clothes on. Thinking about it, we might need a test subject.”

Little Senku smirked as he looked at his friend Taiju, the young boy looking at him with a confused look. It was lunch time at school and even during their breaks, Senku didn’t stop thinking and analyzing about science. Other kids thought he was acting strange but simple rumors didn’t stop him from doing his own thing. Unaware of peering [ e/c ] eyes staring at his direction, the little girl blinks as the white haired male continues to mumble while sipping on his juice box. She looks down at the book she had on her desk before her friends called her over, making her quickly stuff the book into her bag and stand from her seat. Before leaving with them, she takes one last glance at the boy before turning around and leaving the room and chasing after her friends. 

That day, Senku kept staring at the papers with different calculations he had made, still frustrated at the odd numbers that he was getting. All of the other students were filing out of the classroom, soon leaving it to be Senku and the [ h/c ] haired girl. She was the last to put her things away, too caught up on wanting to ask the boy if there was something he needed help with. She looked down at her nervous hands before inhaling sharply and looking directly at the boy sitting a few desks away. 

“Hmm..come on, it’s right on the tip of your tongue..”

“Umm..”

Hearing a new voice, Senku looked up from his work and had noticed a shy [ h/c ] haired girl standing in front of his desk and looking down at her fumbling hands. She didn’t say another word after that, causing the white haired boy to look at her confused. 

“Can I--”

“This number..there’s a decimal there, isn’t there?”

Senku blinks as he looks down at his paper, her finger pointing towards the equation that he was previously glaring at. Senku looks closer and does the math in his head again with a decimal like she had mentioned, his eyes widening as he leans back with his hand face palmed. 

“Oh my god, I can’t believe I missed that!! How did you know?” Senku now averts his eyes towards the girl in front of him, caught by surprise when a question was directed towards her. Her eyes widened as she started to blush with embarrassment, clenching her bag closer to her body by impulse.

“I..I’ve seen that number before everytime my mom and dad work..they always have to make sure it’s the right measurement..so they often repeat that number a lot in case they forget.”

Senku watches her speak as he nods, holding his chin while looking down at the papers in front of him. He was starting to write them down, the sound of the pencil scratching against the paper the only thing surrounding the walls in the empty classroom. She continued to observe him, her embarrassed blush still coating her cheeks as she looked at him.

“I couldn’t believe that something like that slipped my mind. Thanks.”

“Umm, You’re we--”

“SENKU!!”

From the sudden outburst and the slam of the classroom door opening, the [ h/c ] haired girl jumps from where she stood and practically yelps out of fear. Both students look at the culprit and had noticed a brown haired student looking at the others with a confused look as well.

“When will you ever learn to open a door normally, Taiju..”

“Sorry! I noticed that you weren’t following me so I went back to see if you were here! Turns out you were just talking to [ l/n ]-san!”

“Ex-Ex-Excuse me!!” Once the girl had came back to reality, she quickly took her things and practically ran out of the classroom from fright. Both boys had witnessed her leave, Taiju scratching his head as he placed his hands on his hips.

“Hm, that’s kind of weird. What were you two talking about?”

“Nothing much..she just helped me with what I was stuck on.”

“Ah, I see! I knew she was super smart too but she doesn’t talk much!” Senku looks at his friend as he slowly but surely started to pack up his things as well. He looked at the spot that she last stood before looking out the window, the sky slowly transitioning towards an orange color.

“Hm, I see.”

After that fated encounter, Senku had started to notice the [ h/c ] haired girl even more. For some reason his eyes would wander and somehow landed on her, minding her own business. There would be times when all he did was stare at her too, watching her read in the library and turning the page. Senku wasn’t sure what this was but it gave him peace and settled with any emotions that he felt that stirred in his body. Taiju would stare at his friend space out, looking in between the space before he stood from his seat. This caught Senku off guard as he looked at him, the brown haired boy giving him a smile and thumbs up.

“You seem like you want [ l/n ]-san to help with your project! I’ll go ask her!”

“Wait, you idiot!”

But before Taiju could listen to Senku’s response, he quickly leaves his spot and runs over to the [ h/c ] haired girl. Senku only huffed as he returns his gaze back down towards his work, biting down on his pen and trying to go back to where he left off.

“That idiot, she’s probably just going to think it’s boring and not come over.” Senku whispered to himself, tapping his finger against the desk even more. Unaware of his knowledge, Taiju had started to come back, but haven't realized that there was someone following him. Senku looks up from his work once he sees Taiju return to his seat, letting out a sigh.

“Oh, you’re back. She probably said--”

“Umm..”

Hearing a new yet familiar voice, he looks up from his papers and turns to the source of the voice. The [ h/c ] haired girl reaching over and bowing her head slightly. When he looked at her, he had a better view of how she looked like and his eyes were drawn to the color of her eyes. She had a shy gaze, flickering between the seat next to him and back towards his direction.

“O-Oki-kun told me you were working on those math problems..can I help?” Senku looked at her before directing his eyes towards his paper again, mumbling his response to her.

“D-Do what you want..”

The [ h/c ] haired girl felt at ease when he (somewhat) agreed with her question, settling herself down on the seat next to him. She had opened her book that she was reading before, but soon averted her eyes towards the paper he was writing. She looked at the sloppy sketches that he had made on the top left, then pointing some arrows towards each description. She tilts her head to the side before pointing towards the achilles heel, making the white haired boy to stop his writing. 

“That’s not where that description goes, it goes here.”

“Why?”

“E-Eh? We-Well..if you’re going to bring someone down, the popliteal fossa is one way but..to stun the person completely, then the achilles' heel is the best.”

Senku looks at the girl as she was explaining her theory, Taiju that was sitting across from them looking at her with a shocked and confused expression. Senku could only blink as the [ h/c ] haired girl continued to speak, unaware that she was starting to ramble on about different parts of a leg. It wasn’t until Senku smirked and placed his pencil down, crossing his arms over his chest as he leaned back to listen. The girl then caught on with the body language and stopped herself, covering her mouth while her cheeks were starting to flush from embarrassment.

“I-I’m sorry! I shouldn’t have--that was really weird..wasn’t it?”

“What do you mean? Knowing about the human body? That seems normal to me.”

“But..I was using big words earlier and..”

“That was so cool, [ l/n ]-san!! You’re so smart, just like Senku!!” Taiju rose from his seat, earning a stern look from the librarian. All three students slightly ducked their heads and stayed quiet for a moment before Senku looks over at the girl again. Her cheeks were still flushed as she had her gaze looking towards the librarian’s desk. Then, Senku tapped her shoulder to catch her attention which he successfully did. She looked at him as he was holding up the picture of a human diagram, pointing at it. 

“I’m going to be making a wet suit for my dad to help him learn how to swim. Do you want to help?”

The girl saw this as her eyes started to sparkle, a bright smile forming on her lips. She nodded her head, smiling again at the white haired boy who sat on his chair, stunned. His eyes were wide as she held her book close to her body and looked at him with the most color he has ever seen in [ e/c ].

“I’d love to help!”

Hearing her response, Senku smirks as he holds his hand out towards her and making her look down at it. She looks back at him and reaches forward, grabbing his hand. He started to shake her hand, causing her to slightly blush from the interaction.

“The name is Senku. Can’t wait to hear what you know about the human body.” The little girl smiled as he finally introduced his name, causing her to feel joy. 

“My name is [ f/n ]! It’s nice to meet you, Senku-kun.

Their meeting was an odd, but it did form a special bond between the white haired student and the [ h/c ] haired student. As they continued to meet in the library, it had started to become a routine until the very end of their elementary school days. Taiju and Senku later found out that [ f/n ] loved to learn new things, ranging from how to cook different types of food and learning how to shoot a bow in archery. [ f/n ] had started to open up to the male duo, finally becoming herself and not concealing her knowledge with various topics she loves to learn. As the trio continued to grow up together, all three were occupied with various clubs that they joined but they always made sure to meet up somewhere to hang out. But more than not, it was always helping out with Senku and his extreme rocket science projects. 

Senku would never admit it out loud, but having [ f/n ] around had put him at ease. It definitely balanced things out everytime Taiju would boast about something rather _loudly,_ but [ f/n ] would help tone down his loudness by kindly asking him to lower his voice. And even when Taiju didn’t have the time to meet at the usual spot, [ f/n ] would sit quietly and read a book while he was doing his work. There would be times he would sneak a glance over at her direction, noticing the peace and quiet atmosphere that had developed between them and the occasional sound of a page being turned. Senku would look at her, observing her actions as he would feel himself be openly comfortable around her. One day, Taiju was going to meet the two later after clubs so it was just [ f/n ] and Senku sitting at the same table while he was working on a project. Senku decided to steal a glance towards [ f/n ]’s direction and watched her read her book from her side. But as he was observing her, she also looked up from her book after feeling like someone was watching her. After making eye contact with the white haired male, he slightly jumped from his seat and started to tinker with the little gadget he was working on. 

“Is something wrong, Senku? Do you need help?”

“No-Nope! Nope, I’m good.”

[ f/n ] giggled softly as she nodded her head before going back to the original task. After a few more minutes, Senku looked up again to see if she went back to reading but was only caught again when she was looking at him. She was smiling at him, holding her book against her chin as she watched him stiffen from his spot and drop his screwdriver. He looked away with embarrassment as [ f/n ] giggled from the behavior, causing the tips of his ears to redden. 

“So you were looking at me!”

“I was not!”

“Well, did you need something? Do you need some help?”

“..no, I don’t need help with anything.”

“Then..is something wrong..?” [ f/n ] questions as she places her book down, her attention now on the white haired male sitting in front of her. He slowly over to her, her curious [ e/c ] colored eyes looking at him. His fingers reach out to fiddle with his pencil, breaking eye contact here and there.

“Why don’t you hang out with your other club members? You don’t always have to be stuck here. You’re not really doing anything and you’re the type of person to do other things besides just reading in the science lab.”

[ f/n ] blinked as she was processing Senku’s question in her head, her own head tilting her head with confusion. She looked down at the book she was reading, a small smile forming on her lips as she was playing with the pages from the corner of the book.

“I mean..you and Taiju are my friends too. I can’t hang out with you guys?” Senku was about to respond with a counter but when he looked at her, he could probably say that his breath was practically taken away for a split second. [ f/n ] looked at him as she laughed, resting her cheek on her hand as she gave him a teasing smile.

“I’m kidding! I honestly love hanging out with you and Taiju, Senku. If anything, I would rather be here than doing clubs sometimes.”

_ba-bump_

Senku felt his heart beat twice as fast as he continued to stare at her, his hand slightly twitching from the sudden change of heart. His cheeks flushed for a moment before looking away, going back to tinkering with the device in front of him. [ f/n ] sat there patiently as she continued to look at him, soon going back to her original task as she tucks a strand of hair behind her ear.

“D-Do what you want..”

Middle school came and went as the trio only grew closer together, a new addition coming to join their group as Yuzuriha from the crafts club had helped with one of Senku’s insane projects. As they grew older, Senku started to notice the little things about [ f/n ] that made her how she was, appreciating those little things as his heart continued to grow and grow bigger for her. Senku knew himself that love wasn’t scientific, but it was one of those aspects that made somebody human. 

He always thought that falling in love was just an illogical theory that would be just a waste of time and would require energy just to make the other happy. But every time he thought about [ f/n ], he couldn’t help but make her an acception, especially the times when she’d smile at his direction or just sitting comfortably in the same room, unbothered. He was never going to admit it to anybody, even to himself, but his heart would always soar and beat twice as fast every time he was with her. 

The day that Senku can confirm his heart had betrayed him, was a day during their second year of middle school and Senku had invited [ f/n ] to his house. It was normal for Taiju to come over, but it was something new for [ f/n ]. The girl looked at the house, standing in front of the gate as Senku pushed them open and headed straight for his front door. She continued to stay from where she was, Senku looking back after realizing that she wasn’t following him.

“What’s wrong?”

“Ar-Are you sure it’s okay for me to come over? I mean..are you sure??”

[ f/n ] started to panic, the white haired male giving her an unimpressed look. She continued to ramble, unaware of Senku stepping forward and grabbing a hold of her wrist and taking her inside his house. 

“Taiju always comes over so it’s fine for you too.”

“Are you sure, Senku? I mean..”

“[ f/n ], I’ve known you almost as long as I’ve known Taiju. I mean, don’t friends bring other friends over to their houses?”

[ f/n ] couldn’t think of a counter to go against him as she only sighed in defeat. She followed Senku’s movements and took off her shoes as well, the white haired male leading the way inside. She looked around the hallways, the lack of pictures displayed until she had noticed a few laid out on top of the shoe rack. She was about to say something but Senku quickly turns over to look at her, pressing a finger to his lips. After understanding the message, she immediately closed her mouth as he was leading her way towards his room.

“Senku, you home?”

“Yeah I’m home, old man. I’ll be in my room working on something.”

“Is Taiju with you? I’ll prepare some snacks for you guys.”

“That’s okay! I’ll do it myself!!” After finally reaching the top of the stairs, Senku opens the door that was on the far right and ushering her inside. She takes a step inside, looking around at the machinery as he steps inside and sliding the door close behind him. He sighs with relief as he walks over and sits himself down on his desk, his head leaning backwards. [ f/n ] chuckles from the behavior before taking a seat on the floor and leaning her back against his bed.

“Was that your dad?”

“Yeah..he’s normally not home but when he is, he’s honestly a pain.”

“Well..if he’s acting that way, in my opinion means he’s doing his job as a parent.”

“When did you move the enemy side, hm?”

[ f/n ] only laughed as she reached into her bag for her book, and turning back to the page she left off at. Senku observes her as he picked up his bag and starts to take out his things, placing them on his desk. Once he had everything sorted out, he rose from his seat and starts to head towards his door. 

“I’m going to get something to drink, want anything in particular?”

“I’m fine with anything, thank you.” She looks over at him and smiles, causing him to nod with a slight blush on his cheeks. He opens the door and gently closes it, making his way down and towards the kitchen. He takes a peek in his living room, noticing Byakuya yawning from his spot on the couch. 

“There’s some new snacks in the pantry, just make sure to not eat the pink bag, that’s mine.”

“Yeah, yeah.”

Senku calls out as he opens the pantry and starts to search for them. Byakuya slowly peeks from over the couch, noticing his son was preoccupied so he took this chance and quietly left the living room to check the front of the house. He looks down at the shoes laid out and had noticed one of them was smaller than Senku’s. 

“Ah..I knew it was too quiet for the visitor to be Taiju. I need to see this girl for myself!”

Byakuya snickers as he takes a small peek in the kitchen, noticing that Senku was still rummaging through the pantry. Byakuya smirks as he tiptoes up the stairs, making his way towards Senku’s room and slowly opening the door. [ f/n ] was still reading her book from where she sat, gently turning the page as she continued to read. She tucks a piece of her hair behind her ear as she skims down another page. 

_‘OH MY GOD SHE’S GORGEOUS!!’_

As he was mentally complimenting her, he opened the door just a tad bit and caught her attention. She looks up from her book and noticed the older man leaning on the door frame with tears running down his eyes. [ f/n ] blinks as she closes her book and softly clears her throat. This caught Byakuya’s attention as he flinches from the sudden eye contact with Senku’s guest, making her shyly give him a smile. 

“He-Hello, I’m sorry for barging in without a greeting..”

“Don’t worry about it! I’m sorry you had to meet me this way.” Byakuya laughs as he finally enters Senku’s room and closes the door behind him. He takes a seat in front of [ f/n ], the girl softly bowing her head as Byakuya smiles and extends his hand forward for a handshake. 

“My name is Byakuya Ishigami, I’m Senku’s dad. It’s a pleasure meeting you.”

“I-I’m [ l/n ] [ f/n ], Senku’s classmate! It’s a pleasure meeting you as well.”

[ f/n ] meekly shakes his hand as Byakuya gives her a big smile, shaking her hand in return. As the two had started to engrave themselves into a conversation, Senku finally finds the snacks his dad had mentioned. After placing them on the counter, he goes over to open his fridge and starts to search for some drinks for the two of them. 

“Hey old man! We’re running low on tea so I’m grabbing one of your milk teas!”

As Senku calls out to him, he expects a response but was only greeted with silence. Raising a brow with confusion, he looks away from the fridge and closes the door. Placing the cans together with the snacks, he walks over to the living room and checks to see if he was there. But once he saw him not lying on the couch, Senku’s vein almost popped out of anger as he grabbed the snacks from the counter and made a beeline towards his room. Once he makes it to the top, he slams the door open with his free hand and startling the two others inside. [ f/n ] blinks as Byakuya starts to sweat, laughing nervously as he places his hands in the air. 

“Senku, why didn’t you introduce me to [ f/n ]-chan sooner? She’s an amazing person!”

“I know that, so GET OUT!!” Senku fumes as he starts to push Byakuya out the door, the older man waving at the [ h/c ] haired girl. 

“You’re welcome here anytime, [ f/n ]-chan! I hope to see you so—AH!”

With that, Senku was able to successfully push him out and was huffing like a mad man while also trying to catch his breath. He finally composes himself and walks back over to his desk to grab his books and joins [ f/n ] by sitting at the table. He starts to grumble to himself, opening a bag of chips and laying it out in front of them while also opening a can of green tea for himself. [ f/n ] continues to watch him fume, doing her best to stifle her giggle as Senku almost chucked his whole drink. He exhales loudly after drinking some tea, looking over towards [ f/n ]’s direction once he heard a few giggles coming from her way. As Senku looked at her, his cheeks become flustered a little as he starts to calm down but still a bit embarrassed. 

“Wh-What are you laughing at..?”

“You and Byakuya-san must be super close, right?” Senku only scoffs as he grabs another chip and tossing it into his mouth. This only proved [ f/n ]’s theory as she started to giggle again. He grunts as he grabs the can of milk tea and opens it for her, before giving the can to her. She looks down at it owlishly before thanking him and taking the drink. She smiles at the sweet taste, Senku watching her until she puts the can down. He then grabs his book and lays on the floor, his back facing hers. She looks at his direction and smiles, her fingers reaching over and grabbing a chip as well. 

“Is this your way of pouting, Senku?”

“...”

“I’ll take that as a yes then.”

[ f/n ] laughs as she eats another chip and opening her book again. The atmosphere is quiet as they were silently reading, the occasional sound of pages being turned. But after awhile, [ f/n ] yawned and started to the tiredness kicking in. She closes her book and stretches from where she sat, turning her head to look at the white haired male lying on the floor. She takes a glance at the clock and looks over to Senku again, not budging from his spot. 

“Senku..? I’m thinking about taking a break. Maybe you should take one..too..?”

As she peeks over to check up on him, [ f/n ] blinks as she found him softly snoring from his spot. The [ h/c ] haired girl couldn’t help but blush at the innocent look he had while sleeping, making her eyes sparkle. She looks around his room and gazes at him again, a soft smile forming on her lips. She slowly reaches over and lets her hand hesitantly rest on his head, her fingers feeling the softness of hair under her fingertips. She sits a bit closer as she continues to play with his hair, [ f/n ] blushing as she continued to admire how soft it was.

_‘I have no idea what’s in men shampoo products but his hair is so fricken soft!!’_

Senku suddenly stirs in his sleep, catching [ f/n ] by surprise. She yelps when he turns over to look at her while rubbing the sleep in his eyes. [ f/n ] was fumbling with her words as she tried to hide how flustered she looked, Senku looking down at his wrist watch and checking the time. 

“Sorry..I fell asleep for a bit.”

“Th-That’s fine! I wa-was about to wake you up in case you wanted something to eat or anything..!”

Senku grunts as he looks at her tiredly, [ f/n ] starting to ramble again with a flustered look. He groans as he leans closer and lays his head on her lap, causing her to yelp once more by surprise. She looks down at him, his head facing away from her as he crosses his arms over his chest while he gets comfortable again. She watches him close his eyes and exhaled softly, his body falling limp again. 

“Just wake me up in 10 minutes and don’t move. I’m just going to close my eyes..”

Senku sighs as he slightly nuzzled closer, causing [ f/n ] to observe him until he finally decides to fall into slumber. She couldn’t stop herself from blushing as she smiles at him, reaching out and hesitantly resting her hand on his hair again. After receiving no reaction, she continues to stroke his hair, weaving her fingers through his scalp. 

“Goodnight, Senku.” She softly whispered as she closes her eyes, unaware of Senku’s cheeks blossoming a pink hue as she continues to pet his hair. 


End file.
